Outer join can be created using this addition to the
where clause in a select statement. It speeds up the performance tremendously,
but the cons of using this variation are listed below
Duplicates
are automatically removed from the resulting data set. Hence care should be
taken that the unique key of the detail line items should be given in the
select statement.
If the
table on which the For All Entries IN clause is based is empty, all rows are
selected into the destination table. Hence it is advisable to check
before-hand that the first table is not empty.
If the
table on which the For All Entries IN clause is based is very large, the
performance will go down instead of improving. Hence attempt should be made
to keep the table size to a moderate level.
